If, as many expect, a general election is announced on Tuesday we will immediately enter a time known - perhaps bizarrely - as "purdah". Or at least ministers and civil servants will. This is the period, corresponding with the election campaign itself, during which politically sensitive announcements cannot or should not be made.

But is purdah really necessary? I think not. The word itself is problematic, having old colonial overtones and relating to the somewhat controversial practice of women concealing their bodies with veils. It might be wise to avoid the phrase altogether. Certainly the Welsh assembly seems to think so, having recently outlawed the term in favour of the less exotic "pre-election period".

But the real obstacle is more than semantic. It is rather the activity itself - or I should say the lack of activity - which really raises eyebrows. The notion of purdah, of course, is to prevent sitting governments from making attractive policy pronouncements in the runup to the election, thereby boosting their ratings in the polls. The electorate, it is widely assumed, would be unfairly seduced by a last-minute tax cut or new spending announcement on schools or hospitals.

But is the electorate really that gullible? After all, we live in fairly cynical times, when politicians are widely regarded by the public as little more trustworthy than a snake-oil salesman. Would they be so easily taken in by the offer of a few pre-election bribes?

The reality is that the business of government continues during an election campaign. It has to. Ministers are still ministers and civil servants do not suddenly become entitled to a three-week holiday.

What is more, the whole issue of purdah raises some difficult questions, such as do we have a working definition of "politically sensitive"? And if it is disingenuous of a minister to deliberately announce a major policy plank during the campaign is it not equally disingenuous - and perhaps also a little condescending - to deliberately delay it until the results are known?

It's not as if the party manifestos themselves will not be full of alluring proposals. Indeed, that's their whole point. Nor is there a moratorium on the sitting government announcing important changes immediately before purdah kicks in. Gordon Brown's statement on troop withdrawal was just as much about wooing voters as George Osborne's proposal on inheritance tax, and both were allowed, within the rules.

Like most people, I'm all for impartiality. It's one of the great political "hooray" concepts. But there are times when it can be an overrated commodity. Elections are a bit of a bun-fight and are probably all the better for that. What is more, the electorate is switched on and knows a cheap tactic when it sees one.

Back in 1964 the satirical television programme That Was The Week That Was was actually taken off air because producers were worried that it could affect the outcome of the election. They were clearly over-sensitive to the issue of impartiality. Such political censorship did not serve the public well then and does not do so today.